A look at IO.Anywhere modules in the IO Ohio facility in Dayton, Ohio. (Photo: Rich Miller)

The data center and hosting IPOs are beginning to multiply. IO plans an initial public offering of common stock, the company said Friday. The company's filing is confidential and currently being reviewed by the Securities and Exchange Commission, but would be made public for investor review before any IPO.

IO is the third hosting and infrastructure firm that has filed plans to go public. QTS unveiled IPO plans in August, while hosting roll-up Endurance International Group (EIG) announced an IPO filing earlier this month. CyrusOne is the most recent data center firms to have competed an IPO, raising $313 million in its January debut on Wall Street.

The filing is not unexpected,as industry analysts have long speculated that IO was an IPO candidate. Last month IO hired a new CFO with experience at public companies, which is often seen as a precursor to an IPO.

The IPO by IO will provide investors with the first opportunity to invest directly in a "pure play" on the modular data center deployment model which IO has labeled "Data Center 2.0." It also arrives at an opportune time, as Wall Street seems particularly receptive to technology IPOs. On Friday, shares of cybersecurity firm FireEye and advertising tech company RocketFuel both soared 90 percent or more in their first day of trading.

IO was founded in 2007 and has been a pioneer in the emerging market for modular data centers that are built in a factory using repeatable designs and can be shipped to either an IO data center or a customer premises. The company has built two data centers in the Phoenix area, along with facilities in Ohio, New Jersey and Signapore. In addition to its IO.Anywhere modular technology, the company has also developed IO.OS software for managing complex data center infrastructures across multiple sites.

The company has raised at least $250 million in equity funding:

Shortly after its founding in 2008, the company raised $56 million in funding from private equity firm Sterling Partners, which had previously backed the IO team when it developed the Downtown Phoenix Technology Exchange before selling it to Digital Realty Trust in a 2006 transaction valued at $175 million.

In 2011, IO raised $105 million in growth capital from Sterling Partners, J.P. Morgan Asset Management and members of the IO management team.

In Oct. 2012, IO lined up $90 million in equity funding from a group led by New World Ventures, an investment arm of the Pritzker family. The investment round included $50 million from New World and $40 million from IO’s existing backers, which include Sterling Partners and J.P. Morgan Asset Management.

IO has also tapped the debt markets to fund its growth. In May the company arranged a $260 million credit facility led by Wells Fargo, with participation from Mutual Bank of Omaha, Bank of America, Bank of Montreal, JPMorgan Chase Bank, Royal Bank of Canada, National Bank of Arizona, Goldman Sachs Lending Partners and Morgan Stanley Bank.